This invention relates broadly to an exercise machine and, more particularly, pertains to a seated abdominal exercise machine for performing an abdominal "crunching" motion, in which one's abdominal muscles are exercised as the spine is flexed.
Human abdominal muscles are chiefly comprised of the rectus abdominus. The rectus abdominus muscles are a pair of elongated, planar muscles, on either side of the navel, which extend along the entire length at the front of the abdomen from the lower rib cage to the pelvis. The rectus abdominus muscles are interconnected by a band of fibrous connective tissue which creates a greater abdominal region beneath the sternum.
The upper section of the rectus abdominus is known to be effectively exercised by performing repetitions of sit-ups using the "crunch" technique. In its classic context, "crunch" relates to the motion in which the human torso is raised from a lying down or supine position, that is, flexed in a curling motion, while the spine is bent and the legs are held straight or bent.
Damage to the spine can occur when the vertebrae region is subjected to stresses or forces which are inconsistent with the function of that region. Unless care is taken to completely and properly support one's back, neck and head, dangerous stress is placed on the vertebrae and discs.
To minimize the risk of injury and provide a greater level of comfort and control than that achieved from traditional free hand exercises, various devices have been proposed whereby an exerciser can perform or simulate a crunch motion while performing repetition of exercises equivalent to sit-ups or crunches, but remaining within the safe limits of stress to the back, neck and abdominal muscles.
Various resistance-type exercise devices for exercising abdominal muscles have been developed over the years. One type of device is known as a seated abdominal exercise machine. Generally, this type of machine places an exerciser in a sedentary position raised off the ground in a framework, including a rotary-type, upper torso engaging structure which allows the exerciser to bend forwardly into a simulated crunch position against a variable resistance.
Although various attempts have been made to perfect these machines, there remains several disadvantages to their design. Some of these machines emphasize motions which work the hip flexors more than the abdominal region. Other machines concentrate on moving about a particular axis or axes without fully supporting the neck, head and back. Still other versions are limited by other factors such as a limited range of movement, improper backrest and/or seat cushion design. With such predecessor designs, it was entirely possible to work the machine's mechanism with incorrect and incomplete motion because proper torso extension and contraction was not completely studied.
Accordingly, it is desirable to provide an exercise device for doing "crunches" that allows for a full range of abdominal muscle involvement while continuously supporting the neck, head and back of the exerciser. It is also desirable to provide a seated abdominal exercise machine which does not impose undue stress on the exerciser's spine and allows an effective abdominal exercising apparatus which is safe, comfortable and easy to use. It is also desirable to provide an exercise apparatus employing a motion translation arrangement for providing a true crunching motion which will strengthen and develop the entire abdominal region.
It is one object of the present invention to provide an improved apparatus for full range exercise of the abdominal muscles.
It is a further object of the present invention to provide an exercise machine for isolating and strengthening the abdominal muscles that requires the exerciser to perform correct torso extension and contraction.
It is also an object of the present invention to provide a seated exercise abdominal machine for guiding the human body through proper trunk flexion by continuous support of the head, neck and back.
A further object of the present invention is to provide an abdominal exercise machine which acts about several axes of motion to enable the proper flexing of one's spine.
Yet another object of the present invention is to provide an abdominal exercise device having a seat and a backrest located at favorable dispositions, so as to maximize the effect of the crunching motion.
In one aspect of the invention, a seated abdominal exercise machine includes a frame, a seat mounted to the frame and a backrest attached to the frame rearwardly of the seat. An arm and head support assembly is mounted for rotary movement to the frame and provides a resistance adapted to be moved by an exerciser occupied in the seat. A motion translation arrangement is pivotally mounted between the frame and the arm and head support assembly for providing an unrestricted, full range abdominal crunching motion for the seated exerciser. The motion translation arrangement includes a transfer tube having a lower end pivotally connected to the frame about a first fixed horizontal axis passing through the back rest, and an upper end pivotally mounted to the upper arm and head support assembly about a first moving horizontal axis. The motion translation arrangement further includes a transfer link having a lower end pivotally mounted to the arm and head support assembly about a second moving horizontal axis, and an upper end pivotally attached to the frame about a second fixed horizontal axis which is offset relative to the first fixed horizontal axis. The motion translation arrangement further includes a movable vertical leg extending downwardly between the arm and head support assembly and the frame, the leg providing additional resistance during the crunching motion. A structure is pivotally mounted about a third movable horizontal axis on the arm and head support assembly adapted for continuously engaging and supporting the head and neck of the exerciser throughout the full range of the exercise motion. The seat is independently adjustable and is generally declined rearwardly relative to the frame at about 35.degree. from a horizontal plane. The backrest is fixed and is generally angularly disposed relative to the frame at about 45.degree. from a vertical plane. The offset relationship between the first fixed horizontal axis and the second fixed horizontal axis enables the motion translation arrangement to pivot at a greater speed at the second movable horizontal axis than at the first movable horizontal axis. The arm and head support assembly includes a carriage superstructure including a horizontal cross beam having opposite ends to which are fixedly attached a pair of downwardly depending parallel arms, a pair of support braces extending forwardly from the arms for supporting a pair of cushions adapted to be engaged by the elbows of the exerciser. The cross beam includes a pair of handlebars having handle grips adapted to be grasped by the hands of the exerciser during exercise. A U-shaped bracket is pivotally mounted on the handle bars and a head support cushion is attached to the U-shaped bracket and adapted to continuously engage the head of an exerciser during the crunching motion.
The invention further relates to a seated abdominal exercise machine having a frame, a seat mounted on the frame, a back rest attached to the frame and an arm and head support assembly mounted for rotary movement to the frame. The improvement resides in a motion translation arrangement including a series of transfer members pivotally interconnected together between the frame and the arm and head support assembly and moving about a first fixed horizontal axis passing through the backrest, a first movable horizontal axis passing through the arm and head support assembly, a second fixed horizontal axis passing through the frame at a location offset from the first fixed horizontal axis, and a second movable horizontal axis which moves rearwardly and upwardly relative to the frame when a downward force is exerted on the arm and head support assembly. The second fixed horizontal axis is offset above and to the rear of the first fixed horizontal axis. The machine includes a one-piece, flat back rest adapted for continuously supporting the back of an exerciser. A head support is pivotally mounted on the arm and head support assembly and adapted for continuously supporting and adjusting the head of an exerciser during use of the exercise machine.
In another aspect of the invention, an abdominal exercise machine is provided in which the torso of an exerciser is adapted to be flexed. The exercise machine includes a frame, a seat adjustably mounted on the frame, and a backrest mounted to the frame and adapted for continuously supporting the back of an exerciser occupied in seat of the machine. A carriage superstructure is pivotally mounted on the frame and includes a pair of pads adapted to be engaged by the elbows of the exerciser. A motion translation arrangement is pivotally mounted between the frame and the carriage superstructure for enabling unlimited range of abdominal motion. A mechanism is pivotally mounted on the carriage superstructure and adapted to continuously support and adjust an exerciser's head throughout the range of abdominal motion, so that the head will move in a manner consistent with the flexing of the torso.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.